The present invention relates to a collapsible ladder assembly, particularly of the type for use as fire escape.
A main object of the invention lies in providing an improved assembly of the above type wherein the ladder can be compactly collapsed and housed within a container which can readily and easily be opened. The improvement resides especially in the construction of the container of which all of the walls, except the rear wall which is fixed, unfold downwardly to hang from the lower edge of the wall following application of a relatively light pressure on a released piston provided at the top of the container.
Another object resides in that the ladder lies, in collapsed condition, on the bottom wall of the container when the latter is closed so that, as the walls unfold downwardly to open position and including the bottom wall, the ladder spreads out immediately into use condition, being retained at the top on the container rear wall, preferably by means of handles secured to the rear wall.
A further object of the invention is that opening of the container and outward spreading of the ladder are accomplished automatically and quickly under the sole action of gravity so that the only work to be done by the user is to apply the aforesaid light pressure on the release piston, no other operation being necessary on his part.
Yet another object of the invention is in the provision of a fire escape installation for use on a building wall having a number of vertically spaced windows, there being one such collapsible ladder assembly of the improved type provided next to each window and the length of the ladders, in spread out condition, being sufficient for a user to use successive ladders as he climbs down the wall, pressing release pistons of downward ladder containers to cause their opening as he reaches them.
A search was made prior to the drafting of the present application, which search has revealed the following U.S. Pat. Nos.:
1,181,667 of 1916 PA1 1,196,419 of 1916 PA1 2,946,398 of 1960 PA1 3,677,366 of 1972 PA1 4,231,449 of 1980
While, admittedly, the above patents disclose collapsible ladders housed, in non-use condition, in containers that can be opened in various ways, none discloses a structure affording the advantageous objects mentioned above, more specifically the possibility of providing a container which opens following application of a light pressure on a release piston provided at the top of the container, the opening that immediately follows taking place under the sole action of gravity and spreading of the ladder, from collapsed condition, likewise taking place under the sole action of gravity.